Product accumulation systems are routinely used in conjunction with conveyors for the storage and accumulation of product which is fed from an upstream source onto conveyors. In the normal operation of this type system, product is placed on a conveyor at the upstream location, for instance at one operational station, and then transported to a downstream location by conveyor where the next step in the manufacture or distribution of the product is to be accomplished.
It is not uncommon that, during this process, there may be a disruption at a downstream location caused by a malfunction of machinery, some constraining problem, or other circumstance which prevents downstream machine from accepting products. Continued operation of production upstream may result in the build-up of line back pressure which could cause a further problem in permitting the unrestricted movement of product. However, if such a disruption is one which can be addressed relatively quickly, upstream product which normally would be transported to the malfunctioning location, can be received and temporarily stored by an accumulator which is integral to the system.
By employing such an accumulator, the upstream machinery can continue to operate by moving product to the accumulator. Since product movement can continue, there is no build-up of line pressure. Such a system also saves the substantial time and expense which would result in having to shutdown and then restart the entire system, if no accumulator was otherwise available.
As product is being received and retained by the accumulator, the downstream problem can be addressed. When that part of the system resumes full operation, the products stored in the accumulator are released to the downstream destination, with little downtime to the system. Products can also be received and stored at the accumulator in case there is an upstream disruption. In this case, accumulated products could be retained and sent downstream in order to keep the system operational while the upstream problem is being remedied.
There are several types of commonly used accumulator systems which perform the above described functions. However, these systems have significant disadvantages. One such system is an inline conveyor, which allows product to build up either in single file or en masse in front of the constraining operation. If the product is stored in single file, the amount of storage is minimal and the build-up of line pressure can be problematic for the downstream machinery, as well as the product, due to damage. If product is stored inline and en masse, the amount of storage is increased, however, the line pressure increases as well and the added requirement of putting the product back into single file is required. This creates the possibility of lost production due to jamming in the single filer.
A second type is offline storage. These devices store excess products at right angles to the line in mass. As product backs up on the production line, the storage device will allow product flood out onto the planar surface, which is powered away from the line during the period of accumulation. When the stored product is called for, the planar surface reverses direction and the stored product is loaded back onto the production line. This is almost always done in mass and therefore has the same inherent problems with line pressure and single filing requirements as inline storage devices.
A third type uses re-circulating storage. This type of storage device allows products to travel directly from the entry point to the exit point without interrupting the flow, until a need to store product occurs. When it does, product is re-circulated by means of two planar surfaces moving in opposite directions. Product that cannot exit the storage device is allowed to re-circulate onto the planar surface, moving in the direction which is opposite to the direction of discharge. This technique has been very effective in minimizing the amount of line pressure that can build up, as well as incorporating within the device the inherent ability to single file without a separate device to perform this function. However, due to the planar surfaces being adjacent to each other and the requirement that the product reverse direction at either end of the storage device, there are limitations to the size shape and speed of the product which can be stored on such a device. Product instability limits the application of these devices. Another factor, which limits the use of these devices is the noise and label damage generated by product-to-product contact during the re-circulating process. Products such as larger glass containers and the like create noise levels which are not acceptable in normal production environments.
It is thus the object of the present invention to overcome the limitations and disadvantages of prior product conveying and accumulation systems.
It is an object of the present invention to provide a product conveying and accumulation system and method which allows products to be received, stored, and accumulated during the production process, thereby efficiently and effectively reducing the adverse affects of downstream and upstream disruptions, including machine malfunctions, on the output of the production process.
It is a further object of the present invention to provide a product conveying and accumulation system and method in which products of various sizes and shapes have the ability to re-circulate in a system, so as to minimize the build-up of line pressure.
It is still a further object of the present invention to provide a product conveying and accumulation system and method which provides the ability to single file or feed multiple output lanes in single file, or en masse, at speeds much faster than had previously been available, due to the unique re-circulating capacity of the system.
It is another object of the present invention to provide a product conveying and accumulation system and method which allows product unable to be accumulated by prior systems because of the product""s physical instability, to be effectively received, stored, and accumulated without damage to or disruption of the product""s movement, thereby increasing the overall output of the entire production process.
It is still another object of the present invention to provide a product conveying and accumulation system and method which reduces the noise levels while conveying and accumulating during the production process.
It is a further object of the present invention to provide a product conveying and accumulation system and method which reduces product contact during product movement and results in subsequent reduction to product damage and product labeling.
These and other objects are accomplished by the present invention which consists of a product conveying and accumulation system for use with products of various sizes, shapes and stability characteristics. The system comprises multiple moving conveyors, including a first conveyor which transports product from an upstream location. This same conveyor or another conveyor delivers product to a downstream location. An accumulator conveyor, traveling at a substantially similar speed or a designated variable speed as the first conveyor or conveyors, is aligned in the same plane as, is adjacent to, and may mate with the first conveyor at a predetermined location for contiguous movement in the same direction as the first conveyor at this predetermined location. A product guide is provided which allows for the movement of product from the upstream to downstream locations during normal operation and directs product to the accumulator section of the second conveyor when there is a disruption or malfunction downstream. Any product which cannot be accepted downstream is thus accumulated in a designated area and such products are re-circulated to that area and ultimately to the downstream location when the downstream disruption or malfunction is remedied.
Product enters the accumulator and its recirculating conveyor either in single file or in multiple rows either aligned or nested or en masse. Product can be discharged in single file, en masse, or in divided rows, whatever the application requires.
The conveying and accumulation system disclosed by the present invention permits product which is inherently unstable, e.g., lightweight, but top heavy plastic containers with a high center of gravity, to be received, accumulated, and re-circulated, without such product tipping, falling over, and thus disrupting the accumulation and re-circulation process. The configuration of the various conveying elements of the system maintains these products in their upright position throughout the accumulation and re-circulation process.
Novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The invention, itself, however, both as to its design, construction and use, together with the additional features and advantages thereof, are best understood upon review of the following detailed description with reference to the accompanying drawings.